1. Field of the Invention
The present invention relates to an apparatus and method for collecting control data of a control portion (hereinafter referred to as CP) as well as control data of an operating system (hereinafter referred to as OS) in the linkage between the CP and OS in a virtual machine.
Accompanying the trend toward operating a system without interrupting the operation of computers in recent years, it has been demanded to provide a function for easily collecting data in the case of the occurrence of trouble or the like without the need of interrupting the operation of the system. Furthermore, in a virtual machine system having an increased degree of OS/CP linking functionality, it is demanded to simultaneously collect the data of the CP and of the OS in order to maintain reliability in the data collection. Therefore, a function is required to collect data of different environments, i.e., CP and OS in a manner linked to each other.
2. Description of the Related Art
In a case where trouble has developed in software, for example, the contents of the main memory are output to an external memory at the time when the trouble developed and are analyzed in order to investigate the cause of the trouble. The function for outputting the contents of the main memory to the external memory is called a dumping function.
So far, few systems have been employed to effect the dumping in the conventional virtual machine systems. For instance, there has been proposed a system in which when trouble develops under the condition where two OSs are operating under the control of the CP, the contents of the main memory are output at one time to an output medium such as a magnetic tape or a magnetic disk. In this system, however, since the data of these OSs has not been edited, there arise such problems that the required data is incomplete and that the analysis requires laborious work over extended periods of time.
According to another system, the OS outputs the data thereof to an output medium in response to a data collection instruction from an external unit or an internal unit, while the CP quite independently outputs the data thereof to another output medium. However, this system lacks reliability for the collected data since the OS data and the CP data are collected at different times from each other.
According to a further system, the OS outputs its own control data to the output medium upon receipt of a data collection instruction. Further, the OS informs the CP of the data collection instruction to request the dumping of the CP data. The CP outputs the CP data to a separate output medium. This system is capable of dumping the contents of the main memory without interrupting the operation of the system but involves the probability that the data being collected may undergo a change during the dumping and that inconsistency may take place between the OS data and the CP data that are collected.
As a control data collection function other than dumping in the virtual machine system, there is a console display function for displaying the contents of the main memory. However, the console display function is not capable of displaying large amounts of the OS data and the CP data under the condition where the contents of the memory are frozen at a time when trouble has developed.
As described above, the CP has a CP dumping function and the OS has an OS dumping function. However, it is not allowed to simultaneously collect the control data of the OS and the related control data of the CP without interrupting the operation of the computers. That is, since the CP data and the OS data are collected separately, reliability of the data becomes poor and investigation involves is difficult due to inconsistency in the data.